CALCULATION OF BEARING CAPACITY OF ECCENTRICALLY LOADED CONCRETE-FILLED GFRP TUBULAR LONG COLUMNS

A total of 15 concrete-filled glass fiber reinforced polymer(GFRP) tubular columns were tested and the specimens were divided into two groups.One group consisted of 6 specimens considering the eccentricity changes,the other consisted of 9 specimens considering the slenderness ratio changes.The test results showed that the eccentricity and slenderness ratio had great influence on mechanical properties of the concrete-filled GFRP tubular columns.With the increase of eccentricity,the destruction configuration of test specimens took place transformation from compression to tension failure gradually,and with the increasing of the slenderness ratio,the failure form of specimens changed from material damage to the instability destruction.The ultimate bearing capacity also decreased with the increasing of the eccentricity and slenderness ratio,but the amplitude of reducing slowed down.Based on the test data statistical regression,the reduction coefficient of the slenderness ratio and eccentricity of composite columns was obtained,and then the bearing capacity calculation formula of the axis pressure long columns and the eccentric-loaded columns was derived.The calculated results were compared with the experimental results,which showed a good agreement.These indicated that the proposed bearing capacity formula of the composite columns had a certain practical significance．